This invention relates to a fluid power generator system for converting natural energy such as wind into rotary energy to be used as electric energy, and more particularly to a fluid power generator capable of improving power generating efficiency.
As a fluid power generating device which uses operating fluid energy as a driving source to generate electric power, a wind vane generator using wind power has been proposed. In the field of this wind vane generator, with development of aerodynamics in recent years, a wing with air resistance and lifting power has been developed. By adopting it in a wind vane, energy conversion with high efficiency of wind power energy with low density and great variability, which was difficult conventionally, has been enabled.
At present, the main tendency is a wind power generator in several hundreds of KW. In the future, the wind power generator with great rated output will be produced. On the other hand, the generator which converts the rotary energy into electric energy is directly coupled with a wing, power within a range of the rated output is generated.
In a generator used in a conventional fluid power generator, to produce a continuously variable output according to a flow rate in a wide range by one unit generator exceeds a standard manufacturing limit of the generator. This leads to an increase in production cost. Therefore, the standard generator used presently, which rotates fixedly with a fixed output, provides a small range between a cut-in flow rate and a cut-out flow rate and cannot efficiently use the energy of the operating fluid.
An object of this invention is to provide a fluid power generator which can generate electric power with a continuously variable output corresponding to a change in the wide range of operating fluid energy such as wind and produce a maximum output in a specific flow rate of the operating fluid.
In order to attain the above object, there is provided a fluid power generator system including a plurality of generators with different rated outputs which are coupled with a wing axial shaft which is rotated by operative fluid energy serving as a driving source, comprising:
an operating mode in which a continuously variable output corresponding to a wide range of a flow rate is given by selectively combining generators with optimum rated outputs from the plurality of generators according to the flow rate of the operative fluid; and
control means for controlling the operation of each of the generators on the basis of a tip speed calculated from the flow rate of the operative fluid and the number of rotations (rotational speed) of the wing axial shaft, thereby acquiring a maximum output for an individual flow rate of the operative fluid.
Further, there is provided a fluid power generator system including a plurality of fluid power generating units with different rated outputs which are coupled with a wing axial shaft which is rotated by operative fluid energy serving as a driving source, the fluid power generating units being stacked in a plurality of stages, comprising:
an operating mode in which a continuously variable output corresponding to a wide range of a flow rate is given by selectively combining generators with optimum rated outputs from the plurality of generators according to the flow rate of the operative fluid; and
control means for controlling the operation of each of the generators on the basis of a tip speed calculated from the flow rate of the operative fluid and the number of rotations of the wing axial shaft, thereby acquiring a maximum output for an individual flow rate of the operative fluid.
Further, there is provided a fluid power generator system including a plurality of wing axial shafts which stand upright coaxially and rotatably to rotate by operative fluid energy serving as a driving source, a plurality of rotary wings having linear blades attached to the wing axial shafts in a plurality of stages, respectively; and a plurality of generators with different rated outputs which are coupled with the axial shafts, respectively, comprising:
an operating mode in which a continuously variable output corresponding to a wide range of a flow rate is given by selectively combining generators with optimum rated outputs from the plurality of generators according to the flow rate of the operative fluid; and
control means for controlling the operation of each of the generators on the basis of a tip speed calculated from the flow rate of the operative fluid and the number of rotations of the wing axial shaft, thereby acquiring a maximum output for an individual flow rate of the operative fluid.
In the fluid power generator system, the control means controls the operation of each of the generators in the operating mode on the basis of a tip speed ratio calculated from the flow rate of the operative fluid and higher number of rotations exceeding an output peak value at the number of rotations of the wing axial shaft.
In the fluid power generator system, the fluid power generating units with different rated outputs stacked in a plurality of stages are arranged to provide rated outputs changed according to a height of a position of each stage.